1. Field of the Invention
The present invention relates to an apparatus for reclaiming wet concrete. Specifically, the invention includes a feed hopper with a screw conveyor, inner and outer concentric mesh cylinders for separating the concrete into its components, washing means, and a means for separating the individual components from the water.
2. Description of the Related Art
Methods of separating concrete into its individual components have been proposed, which components can then be stored and re-mixed at a later date. However, as compared to the other developments, the current invention has the advantages of providing controlled feeding of concrete into the separation apparatus, simultaneous washing and separation of the concrete, and improved means for removing water from the sand.
U.S. Pat. No. 1,458,387, issued to Charles L. Bourne on Jun. 12, 1923, describes a process for treating concrete aggregate. The aggregate is placed in a drum rotating at a high speed, so that the individual particles are thrown against the sides at high speed. The less desirable softer particles will be broken up into small pieces, while the more desirable hard particles will remain intact. The large and small particles can then be separated. This patent does not disclose a pair of concentric mesh cylinders for separating concrete.
U.S. Pat. No. 1,461,067, issued to Robert W. Moser on Jul. 10, 1923, describes an apparatus for treating sand and gravel. The sand and gravel are dumped onto a shaker screen from an elevated position, separating the larger gravel from the smaller sand. The sand passes through additional screens, separating the sand into different sized particles. The gravel is discharged into an agitator where it is washed. This patent does not disclose an apparatus capable of washing and separating the concrete at the same time.
U.S. Pat. No. 4,062,497, issued to Dennis E. Kemp Jr. on Dec. 13, 1977, describes a mill system having a proportioning feeder. A ball or rod mill sends particles to an air classifier, which sends oversized particles back to the mill along with the raw materials. The raw materials are fed into the space at the upper portion of the volumetric feeder above the oversized particles, so that the amount of raw materials sent to the mill is dependant on the amount of oversized particles already in the volumetric feeder. This patent does not disclose a pair of concentric mesh cylinders for separating concrete into its individual components.
U.S. Pat. No. 4,418,871, issued to Stuart A. Powell on Dec. 6, 1983, describes an apparatus for reducing mineral crystalline material. The minerals are first directed through a milling device wherein a turbine sets up a shock wave to break up the particles. The particles then go to a classifier having a series of vertical baffles, where they go through a series of vertical motion reverses, eventually falling into a hopper containing like-sized particles.
U.S. Pat. No. 4,616,786, issued to Rudolf Riker on Oct. 14, 1986, describes a plant for processing surplus concrete. Concrete is deposited from trucks into a receiving bin having a screw conveyor along the bottom. The screw conveyor drives the concrete to a cylindrical washer. The screw conveyor's speed is decreased as electrical consumption of the washer increases, maintaining a relatively constant throughput for the washer. This patent does not disclose concentric mesh cylinders for separating the concrete.
U.S. Pat. No. 5,108,584, issued to Raymond Brosseuk on Apr. 28, 1992, describes an apparatus for extracting heavy metals from ore. The apparatus has two concentric drums oriented at an angle of 2.degree. to 15.degree. from horizontal. The outer drum has an inner spiral vane. The inner drum has an upper fragmentation section with inwardly directed, longitudinally oriented impact vanes, a center trommel section having fine perforations at its upper end and coarse perforations at its lower end, and a lower discharge section. A sluice box is positioned to receive discharges from the upper end of the outer drum. The sluce box has a plurality of offset landings, with the upper landings intended to collect the coarser particles. The ore is separated into large tailings which are discharged from the lower end of the inner drum, and heavy, fine particles which are discharged from the top of the inner drum into the top of the sluce box.
U.S. Pat. No. 5,234,172, issued to David E. Chupka on Aug. 10, 1993, describes a method of cutting paper using a high pressure water stream.
U.S. Pat. No. 5,312,051, issued to Mark A. Preisser (the present inventor) on May 17, 1994, describes a fresh wet concrete reclaimer. The concrete reclaimer has a rotating cylindrical screen angled between 1.degree. and 10.degree. from horizontal, and a spray bar. The screen rotates rapidly enough so that the concrete is carried up to a point 90.degree. from the bottom. Sprayed water is directed towards the middle of the mass of concrete. The upper end of the screen is made from fine mesh which allows cement slurry to pass through it. The lower mesh is made from coarser mesh, allowing sand to pass through it. Gravel exits the opposite end of the screen. This patent does not disclose the use of concentric mesh cylinders to separate the concrete.
U.S. Pat. No. 5,441,415, issued to Steinar Storruste and Mark A. Preisser (the present inventor) on Aug. 15, 1995, describes a centrifugal separator having a pair of mating horizontal frustroconical bowls, having concentric inlet and outlet pipes and wherein the top bowl is held against the bottom bowl by a spring. A baffle fits inside the bowls. A slurry enters through the inlet pipe, and the spinning of the bowls causes the more dense particles to move towards the outside. Sufficient rotational force causes the bowls to separate, allowing the heaviest particles to exit. Liquid exits through the central outlet pipe. This patent fails to disclose a pair of concentric mesh cylinders for separating the concrete.
U.S. Pat. No. 5,540,395, issued to Henry S. Branscome on Jul. 30, 1996, describes a concrete reclaimer comprising a rotating cylinder having a closed chamber and a screen chamber. Concrete is introduced to the closed chamber along with water, producing a slurry. The slurry is floated out of the closed chamber. The remaining sand and gravel is transferred to the screen chamber by four blades. The sand goes through the screen, and the gravel goes out the end of the reclaimer. This patent fails to disclose a pair of concentric mesh cylinders for separating the concrete.
U.S. Pat. No. 5,613,902, issued to Michael S. Didion et al. on Mar. 25, 1997, describes a sand reclaimer. The sand reclaimer has concentric inner and outer cylinders. The inner cylinder is perforated to allow sand to pass through to the outer cylinder. A helical vane on the inside of the inner cylinder pushes sand towards the outlet, and a second helical vane on the outside of the inner cylinder pushes sand towards the inlet. Large perforations at the end of the inner cylinder allow large particles of sand to pass through, and castings come out the outlet. At the inlet, a dust cover allows small particles of sand to exit the reclaimer for collection, while larger particles are directed back to the inner cylinder at the inlet for further tumbling. This patent does not disclose a means for simultaneously washing and separating concrete aggregate, or for removing water from the components after separation.
U.S. Pat. No. 5,624,077, issued to henry S. Branscome on Apr. 29, 1997, describes a concrete reclaimer comprising a rotating cylinder having a closed chamber and a screen chamber. Concrete is introduced to the closed chamber along with water, producing a slurry. The slurry is floated out of the closed chamber. The remaining sand and gravel is transferred to the screen chamber by eight blades. The sand goes through the screen, and the gravel goes out the end of the reclaimer. This patent does not disclose a pair of concentric mesh cylinders for separating concrete slurry.
U.S. Pat. No. 5,685,978, issued to Harold W. Petrick et al. on Nov. 11, 1997, describes a concrete reclaimer having a tank with two sections, and a pivoting screen between the two sections. Small particles filter through the screen into the first section, and large particles are dumped into the second section by pivoting the screen. This patent does not disclose a pair of concentric mesh cylinders for separating concrete slurry.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a axial flow, bi-rotor concrete reclaimer solving the aforementioned problems is desired.